linux/include/linux/mmzone.h
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   1#ifndef _LINUX_MMZONE_H
   2#define _LINUX_MMZONE_H
   3
   4#ifndef __ASSEMBLY__
   5#ifndef __GENERATING_BOUNDS_H
   6
   7#include <linux/spinlock.h>
   8#include <linux/list.h>
   9#include <linux/wait.h>
  10#include <linux/bitops.h>
  11#include <linux/cache.h>
  12#include <linux/threads.h>
  13#include <linux/numa.h>
  14#include <linux/init.h>
  15#include <linux/seqlock.h>
  16#include <linux/nodemask.h>
  17#include <linux/pageblock-flags.h>
  18#include <linux/bounds.h>
  19#include <asm/atomic.h>
  20#include <asm/page.h>
  21
  22/* Free memory management - zoned buddy allocator.  */
  23#ifndef CONFIG_FORCE_MAX_ZONEORDER
  24#define MAX_ORDER 11
  25#else
  26#define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
  27#endif
  28#define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1))
  29
  30/*
  31 * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed
  32 * costly to service.  That is between allocation orders which should
  33 * coelesce naturally under reasonable reclaim pressure and those which
  34 * will not.
  35 */
  36#define PAGE_ALLOC_COSTLY_ORDER 3
  37
  38#define MIGRATE_UNMOVABLE     0
  39#define MIGRATE_RECLAIMABLE   1
  40#define MIGRATE_MOVABLE       2
  41#define MIGRATE_RESERVE       3
  42#define MIGRATE_ISOLATE       4 /* can't allocate from here */
  43#define MIGRATE_TYPES         5
  44
  45#define for_each_migratetype_order(order, type) \
  46        for (order = 0; order < MAX_ORDER; order++) \
  47                for (type = 0; type < MIGRATE_TYPES; type++)
  48
  49extern int page_group_by_mobility_disabled;
  50
  51static inline int get_pageblock_migratetype(struct page *page)
  52{
  53        if (unlikely(page_group_by_mobility_disabled))
  54                return MIGRATE_UNMOVABLE;
  55
  56        return get_pageblock_flags_group(page, PB_migrate, PB_migrate_end);
  57}
  58
  59struct free_area {
  60        struct list_head        free_list[MIGRATE_TYPES];
  61        unsigned long           nr_free;
  62};
  63
  64struct pglist_data;
  65
  66/*
  67 * zone->lock and zone->lru_lock are two of the hottest locks in the kernel.
  68 * So add a wild amount of padding here to ensure that they fall into separate
  69 * cachelines.  There are very few zone structures in the machine, so space
  70 * consumption is not a concern here.
  71 */
  72#if defined(CONFIG_SMP)
  73struct zone_padding {
  74        char x[0];
  75} ____cacheline_internodealigned_in_smp;
  76#define ZONE_PADDING(name)      struct zone_padding name;
  77#else
  78#define ZONE_PADDING(name)
  79#endif
  80
  81enum zone_stat_item {
  82        /* First 128 byte cacheline (assuming 64 bit words) */
  83        NR_FREE_PAGES,
  84        NR_INACTIVE,
  85        NR_ACTIVE,
  86        NR_ANON_PAGES,  /* Mapped anonymous pages */
  87        NR_FILE_MAPPED, /* pagecache pages mapped into pagetables.
  88                           only modified from process context */
  89        NR_FILE_PAGES,
  90        NR_FILE_DIRTY,
  91        NR_WRITEBACK,
  92        /* Second 128 byte cacheline */
  93        NR_SLAB_RECLAIMABLE,
  94        NR_SLAB_UNRECLAIMABLE,
  95        NR_PAGETABLE,           /* used for pagetables */
  96        NR_UNSTABLE_NFS,        /* NFS unstable pages */
  97        NR_BOUNCE,
  98        NR_VMSCAN_WRITE,
  99        NR_WRITEBACK_TEMP,      /* Writeback using temporary buffers */
 100#ifdef CONFIG_NUMA
 101        NUMA_HIT,               /* allocated in intended node */
 102        NUMA_MISS,              /* allocated in non intended node */
 103        NUMA_FOREIGN,           /* was intended here, hit elsewhere */
 104        NUMA_INTERLEAVE_HIT,    /* interleaver preferred this zone */
 105        NUMA_LOCAL,             /* allocation from local node */
 106        NUMA_OTHER,             /* allocation from other node */
 107#endif
 108        NR_VM_ZONE_STAT_ITEMS };
 109
 110struct per_cpu_pages {
 111        int count;              /* number of pages in the list */
 112        int high;               /* high watermark, emptying needed */
 113        int batch;              /* chunk size for buddy add/remove */
 114        struct list_head list;  /* the list of pages */
 115};
 116
 117struct per_cpu_pageset {
 118        struct per_cpu_pages pcp;
 119#ifdef CONFIG_NUMA
 120        s8 expire;
 121#endif
 122#ifdef CONFIG_SMP
 123        s8 stat_threshold;
 124        s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
 125#endif
 126} ____cacheline_aligned_in_smp;
 127
 128#ifdef CONFIG_NUMA
 129#define zone_pcp(__z, __cpu) ((__z)->pageset[(__cpu)])
 130#else
 131#define zone_pcp(__z, __cpu) (&(__z)->pageset[(__cpu)])
 132#endif
 133
 134#endif /* !__GENERATING_BOUNDS.H */
 135
 136enum zone_type {
 137#ifdef CONFIG_ZONE_DMA
 138        /*
 139         * ZONE_DMA is used when there are devices that are not able
 140         * to do DMA to all of addressable memory (ZONE_NORMAL). Then we
 141         * carve out the portion of memory that is needed for these devices.
 142         * The range is arch specific.
 143         *
 144         * Some examples
 145         *
 146         * Architecture         Limit
 147         * ---------------------------
 148         * parisc, ia64, sparc  <4G
 149         * s390                 <2G
 150         * arm                  Various
 151         * alpha                Unlimited or 0-16MB.
 152         *
 153         * i386, x86_64 and multiple other arches
 154         *                      <16M.
 155         */
 156        ZONE_DMA,
 157#endif
 158#ifdef CONFIG_ZONE_DMA32
 159        /*
 160         * x86_64 needs two ZONE_DMAs because it supports devices that are
 161         * only able to do DMA to the lower 16M but also 32 bit devices that
 162         * can only do DMA areas below 4G.
 163         */
 164        ZONE_DMA32,
 165#endif
 166        /*
 167         * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
 168         * performed on pages in ZONE_NORMAL if the DMA devices support
 169         * transfers to all addressable memory.
 170         */
 171        ZONE_NORMAL,
 172#ifdef CONFIG_HIGHMEM
 173        /*
 174         * A memory area that is only addressable by the kernel through
 175         * mapping portions into its own address space. This is for example
 176         * used by i386 to allow the kernel to address the memory beyond
 177         * 900MB. The kernel will set up special mappings (page
 178         * table entries on i386) for each page that the kernel needs to
 179         * access.
 180         */
 181        ZONE_HIGHMEM,
 182#endif
 183        ZONE_MOVABLE,
 184        __MAX_NR_ZONES
 185};
 186
 187#ifndef __GENERATING_BOUNDS_H
 188
 189/*
 190 * When a memory allocation must conform to specific limitations (such
 191 * as being suitable for DMA) the caller will pass in hints to the
 192 * allocator in the gfp_mask, in the zone modifier bits.  These bits
 193 * are used to select a priority ordered list of memory zones which
 194 * match the requested limits. See gfp_zone() in include/linux/gfp.h
 195 */
 196
 197#if MAX_NR_ZONES < 2
 198#define ZONES_SHIFT 0
 199#elif MAX_NR_ZONES <= 2
 200#define ZONES_SHIFT 1
 201#elif MAX_NR_ZONES <= 4
 202#define ZONES_SHIFT 2
 203#else
 204#error ZONES_SHIFT -- too many zones configured adjust calculation
 205#endif
 206
 207struct zone {
 208        /* Fields commonly accessed by the page allocator */
 209        unsigned long           pages_min, pages_low, pages_high;
 210        /*
 211         * We don't know if the memory that we're going to allocate will be freeable
 212         * or/and it will be released eventually, so to avoid totally wasting several
 213         * GB of ram we must reserve some of the lower zone memory (otherwise we risk
 214         * to run OOM on the lower zones despite there's tons of freeable ram
 215         * on the higher zones). This array is recalculated at runtime if the
 216         * sysctl_lowmem_reserve_ratio sysctl changes.
 217         */
 218        unsigned long           lowmem_reserve[MAX_NR_ZONES];
 219
 220#ifdef CONFIG_NUMA
 221        int node;
 222        /*
 223         * zone reclaim becomes active if more unmapped pages exist.
 224         */
 225        unsigned long           min_unmapped_pages;
 226        unsigned long           min_slab_pages;
 227        struct per_cpu_pageset  *pageset[NR_CPUS];
 228#else
 229        struct per_cpu_pageset  pageset[NR_CPUS];
 230#endif
 231        /*
 232         * free areas of different sizes
 233         */
 234        spinlock_t              lock;
 235#ifdef CONFIG_MEMORY_HOTPLUG
 236        /* see spanned/present_pages for more description */
 237        seqlock_t               span_seqlock;
 238#endif
 239        struct free_area        free_area[MAX_ORDER];
 240
 241#ifndef CONFIG_SPARSEMEM
 242        /*
 243         * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
 244         * In SPARSEMEM, this map is stored in struct mem_section
 245         */
 246        unsigned long           *pageblock_flags;
 247#endif /* CONFIG_SPARSEMEM */
 248
 249
 250        ZONE_PADDING(_pad1_)
 251
 252        /* Fields commonly accessed by the page reclaim scanner */
 253        spinlock_t              lru_lock;       
 254        struct list_head        active_list;
 255        struct list_head        inactive_list;
 256        unsigned long           nr_scan_active;
 257        unsigned long           nr_scan_inactive;
 258        unsigned long           pages_scanned;     /* since last reclaim */
 259        unsigned long           flags;             /* zone flags, see below */
 260
 261        /* Zone statistics */
 262        atomic_long_t           vm_stat[NR_VM_ZONE_STAT_ITEMS];
 263
 264        /*
 265         * prev_priority holds the scanning priority for this zone.  It is
 266         * defined as the scanning priority at which we achieved our reclaim
 267         * target at the previous try_to_free_pages() or balance_pgdat()
 268         * invokation.
 269         *
 270         * We use prev_priority as a measure of how much stress page reclaim is
 271         * under - it drives the swappiness decision: whether to unmap mapped
 272         * pages.
 273         *
 274         * Access to both this field is quite racy even on uniprocessor.  But
 275         * it is expected to average out OK.
 276         */
 277        int prev_priority;
 278
 279
 280        ZONE_PADDING(_pad2_)
 281        /* Rarely used or read-mostly fields */
 282
 283        /*
 284         * wait_table           -- the array holding the hash table
 285         * wait_table_hash_nr_entries   -- the size of the hash table array
 286         * wait_table_bits      -- wait_table_size == (1 << wait_table_bits)
 287         *
 288         * The purpose of all these is to keep track of the people
 289         * waiting for a page to become available and make them
 290         * runnable again when possible. The trouble is that this
 291         * consumes a lot of space, especially when so few things
 292         * wait on pages at a given time. So instead of using
 293         * per-page waitqueues, we use a waitqueue hash table.
 294         *
 295         * The bucket discipline is to sleep on the same queue when
 296         * colliding and wake all in that wait queue when removing.
 297         * When something wakes, it must check to be sure its page is
 298         * truly available, a la thundering herd. The cost of a
 299         * collision is great, but given the expected load of the
 300         * table, they should be so rare as to be outweighed by the
 301         * benefits from the saved space.
 302         *
 303         * __wait_on_page_locked() and unlock_page() in mm/filemap.c, are the
 304         * primary users of these fields, and in mm/page_alloc.c
 305         * free_area_init_core() performs the initialization of them.
 306         */
 307        wait_queue_head_t       * wait_table;
 308        unsigned long           wait_table_hash_nr_entries;
 309        unsigned long           wait_table_bits;
 310
 311        /*
 312         * Discontig memory support fields.
 313         */
 314        struct pglist_data      *zone_pgdat;
 315        /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
 316        unsigned long           zone_start_pfn;
 317
 318        /*
 319         * zone_start_pfn, spanned_pages and present_pages are all
 320         * protected by span_seqlock.  It is a seqlock because it has
 321         * to be read outside of zone->lock, and it is done in the main
 322         * allocator path.  But, it is written quite infrequently.
 323         *
 324         * The lock is declared along with zone->lock because it is
 325         * frequently read in proximity to zone->lock.  It's good to
 326         * give them a chance of being in the same cacheline.
 327         */
 328        unsigned long           spanned_pages;  /* total size, including holes */
 329        unsigned long           present_pages;  /* amount of memory (excluding holes) */
 330
 331        /*
 332         * rarely used fields:
 333         */
 334        const char              *name;
 335} ____cacheline_internodealigned_in_smp;
 336
 337typedef enum {
 338        ZONE_ALL_UNRECLAIMABLE,         /* all pages pinned */
 339        ZONE_RECLAIM_LOCKED,            /* prevents concurrent reclaim */
 340        ZONE_OOM_LOCKED,                /* zone is in OOM killer zonelist */
 341} zone_flags_t;
 342
 343static inline void zone_set_flag(struct zone *zone, zone_flags_t flag)
 344{
 345        set_bit(flag, &zone->flags);
 346}
 347
 348static inline int zone_test_and_set_flag(struct zone *zone, zone_flags_t flag)
 349{
 350        return test_and_set_bit(flag, &zone->flags);
 351}
 352
 353static inline void zone_clear_flag(struct zone *zone, zone_flags_t flag)
 354{
 355        clear_bit(flag, &zone->flags);
 356}
 357
 358static inline int zone_is_all_unreclaimable(const struct zone *zone)
 359{
 360        return test_bit(ZONE_ALL_UNRECLAIMABLE, &zone->flags);
 361}
 362
 363static inline int zone_is_reclaim_locked(const struct zone *zone)
 364{
 365        return test_bit(ZONE_RECLAIM_LOCKED, &zone->flags);
 366}
 367
 368static inline int zone_is_oom_locked(const struct zone *zone)
 369{
 370        return test_bit(ZONE_OOM_LOCKED, &zone->flags);
 371}
 372
 373/*
 374 * The "priority" of VM scanning is how much of the queues we will scan in one
 375 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
 376 * queues ("queue_length >> 12") during an aging round.
 377 */
 378#define DEF_PRIORITY 12
 379
 380/* Maximum number of zones on a zonelist */
 381#define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
 382
 383#ifdef CONFIG_NUMA
 384
 385/*
 386 * The NUMA zonelists are doubled becausse we need zonelists that restrict the
 387 * allocations to a single node for GFP_THISNODE.
 388 *
 389 * [0]  : Zonelist with fallback
 390 * [1]  : No fallback (GFP_THISNODE)
 391 */
 392#define MAX_ZONELISTS 2
 393
 394
 395/*
 396 * We cache key information from each zonelist for smaller cache
 397 * footprint when scanning for free pages in get_page_from_freelist().
 398 *
 399 * 1) The BITMAP fullzones tracks which zones in a zonelist have come
 400 *    up short of free memory since the last time (last_fullzone_zap)
 401 *    we zero'd fullzones.
 402 * 2) The array z_to_n[] maps each zone in the zonelist to its node
 403 *    id, so that we can efficiently evaluate whether that node is
 404 *    set in the current tasks mems_allowed.
 405 *
 406 * Both fullzones and z_to_n[] are one-to-one with the zonelist,
 407 * indexed by a zones offset in the zonelist zones[] array.
 408 *
 409 * The get_page_from_freelist() routine does two scans.  During the
 410 * first scan, we skip zones whose corresponding bit in 'fullzones'
 411 * is set or whose corresponding node in current->mems_allowed (which
 412 * comes from cpusets) is not set.  During the second scan, we bypass
 413 * this zonelist_cache, to ensure we look methodically at each zone.
 414 *
 415 * Once per second, we zero out (zap) fullzones, forcing us to
 416 * reconsider nodes that might have regained more free memory.
 417 * The field last_full_zap is the time we last zapped fullzones.
 418 *
 419 * This mechanism reduces the amount of time we waste repeatedly
 420 * reexaming zones for free memory when they just came up low on
 421 * memory momentarilly ago.
 422 *
 423 * The zonelist_cache struct members logically belong in struct
 424 * zonelist.  However, the mempolicy zonelists constructed for
 425 * MPOL_BIND are intentionally variable length (and usually much
 426 * shorter).  A general purpose mechanism for handling structs with
 427 * multiple variable length members is more mechanism than we want
 428 * here.  We resort to some special case hackery instead.
 429 *
 430 * The MPOL_BIND zonelists don't need this zonelist_cache (in good
 431 * part because they are shorter), so we put the fixed length stuff
 432 * at the front of the zonelist struct, ending in a variable length
 433 * zones[], as is needed by MPOL_BIND.
 434 *
 435 * Then we put the optional zonelist cache on the end of the zonelist
 436 * struct.  This optional stuff is found by a 'zlcache_ptr' pointer in
 437 * the fixed length portion at the front of the struct.  This pointer
 438 * both enables us to find the zonelist cache, and in the case of
 439 * MPOL_BIND zonelists, (which will just set the zlcache_ptr to NULL)
 440 * to know that the zonelist cache is not there.
 441 *
 442 * The end result is that struct zonelists come in two flavors:
 443 *  1) The full, fixed length version, shown below, and
 444 *  2) The custom zonelists for MPOL_BIND.
 445 * The custom MPOL_BIND zonelists have a NULL zlcache_ptr and no zlcache.
 446 *
 447 * Even though there may be multiple CPU cores on a node modifying
 448 * fullzones or last_full_zap in the same zonelist_cache at the same
 449 * time, we don't lock it.  This is just hint data - if it is wrong now
 450 * and then, the allocator will still function, perhaps a bit slower.
 451 */
 452
 453
 454struct zonelist_cache {
 455        unsigned short z_to_n[MAX_ZONES_PER_ZONELIST];          /* zone->nid */
 456        DECLARE_BITMAP(fullzones, MAX_ZONES_PER_ZONELIST);      /* zone full? */
 457        unsigned long last_full_zap;            /* when last zap'd (jiffies) */
 458};
 459#else
 460#define MAX_ZONELISTS 1
 461struct zonelist_cache;
 462#endif
 463
 464/*
 465 * This struct contains information about a zone in a zonelist. It is stored
 466 * here to avoid dereferences into large structures and lookups of tables
 467 */
 468struct zoneref {
 469        struct zone *zone;      /* Pointer to actual zone */
 470        int zone_idx;           /* zone_idx(zoneref->zone) */
 471};
 472
 473/*
 474 * One allocation request operates on a zonelist. A zonelist
 475 * is a list of zones, the first one is the 'goal' of the
 476 * allocation, the other zones are fallback zones, in decreasing
 477 * priority.
 478 *
 479 * If zlcache_ptr is not NULL, then it is just the address of zlcache,
 480 * as explained above.  If zlcache_ptr is NULL, there is no zlcache.
 481 * *
 482 * To speed the reading of the zonelist, the zonerefs contain the zone index
 483 * of the entry being read. Helper functions to access information given
 484 * a struct zoneref are
 485 *
 486 * zonelist_zone()      - Return the struct zone * for an entry in _zonerefs
 487 * zonelist_zone_idx()  - Return the index of the zone for an entry
 488 * zonelist_node_idx()  - Return the index of the node for an entry
 489 */
 490struct zonelist {
 491        struct zonelist_cache *zlcache_ptr;                  // NULL or &zlcache
 492        struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
 493#ifdef CONFIG_NUMA
 494        struct zonelist_cache zlcache;                       // optional ...
 495#endif
 496};
 497
 498#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
 499struct node_active_region {
 500        unsigned long start_pfn;
 501        unsigned long end_pfn;
 502        int nid;
 503};
 504#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
 505
 506#ifndef CONFIG_DISCONTIGMEM
 507/* The array of struct pages - for discontigmem use pgdat->lmem_map */
 508extern struct page *mem_map;
 509#endif
 510
 511/*
 512 * The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM
 513 * (mostly NUMA machines?) to denote a higher-level memory zone than the
 514 * zone denotes.
 515 *
 516 * On NUMA machines, each NUMA node would have a pg_data_t to describe
 517 * it's memory layout.
 518 *
 519 * Memory statistics and page replacement data structures are maintained on a
 520 * per-zone basis.
 521 */
 522struct bootmem_data;
 523typedef struct pglist_data {
 524        struct zone node_zones[MAX_NR_ZONES];
 525        struct zonelist node_zonelists[MAX_ZONELISTS];
 526        int nr_zones;
 527#ifdef CONFIG_FLAT_NODE_MEM_MAP
 528        struct page *node_mem_map;
 529#endif
 530        struct bootmem_data *bdata;
 531#ifdef CONFIG_MEMORY_HOTPLUG
 532        /*
 533         * Must be held any time you expect node_start_pfn, node_present_pages
 534         * or node_spanned_pages stay constant.  Holding this will also
 535         * guarantee that any pfn_valid() stays that way.
 536         *
 537         * Nests above zone->lock and zone->size_seqlock.
 538         */
 539        spinlock_t node_size_lock;
 540#endif
 541        unsigned long node_start_pfn;
 542        unsigned long node_present_pages; /* total number of physical pages */
 543        unsigned long node_spanned_pages; /* total size of physical page
 544                                             range, including holes */
 545        int node_id;
 546        wait_queue_head_t kswapd_wait;
 547        struct task_struct *kswapd;
 548        int kswapd_max_order;
 549} pg_data_t;
 550
 551#define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
 552#define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
 553#ifdef CONFIG_FLAT_NODE_MEM_MAP
 554#define pgdat_page_nr(pgdat, pagenr)    ((pgdat)->node_mem_map + (pagenr))
 555#else
 556#define pgdat_page_nr(pgdat, pagenr)    pfn_to_page((pgdat)->node_start_pfn + (pagenr))
 557#endif
 558#define nid_page_nr(nid, pagenr)        pgdat_page_nr(NODE_DATA(nid),(pagenr))
 559
 560#include <linux/memory_hotplug.h>
 561
 562void get_zone_counts(unsigned long *active, unsigned long *inactive,
 563                        unsigned long *free);
 564void build_all_zonelists(void);
 565void wakeup_kswapd(struct zone *zone, int order);
 566int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
 567                int classzone_idx, int alloc_flags);
 568enum memmap_context {
 569        MEMMAP_EARLY,
 570        MEMMAP_HOTPLUG,
 571};
 572extern int init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
 573                                     unsigned long size,
 574                                     enum memmap_context context);
 575
 576#ifdef CONFIG_HAVE_MEMORY_PRESENT
 577void memory_present(int nid, unsigned long start, unsigned long end);
 578#else
 579static inline void memory_present(int nid, unsigned long start, unsigned long end) {}
 580#endif
 581
 582#ifdef CONFIG_NEED_NODE_MEMMAP_SIZE
 583unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
 584#endif
 585
 586/*
 587 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
 588 */
 589#define zone_idx(zone)          ((zone) - (zone)->zone_pgdat->node_zones)
 590
 591static inline int populated_zone(struct zone *zone)
 592{
 593        return (!!zone->present_pages);
 594}
 595
 596extern int movable_zone;
 597
 598static inline int zone_movable_is_highmem(void)
 599{
 600#if defined(CONFIG_HIGHMEM) && defined(CONFIG_ARCH_POPULATES_NODE_MAP)
 601        return movable_zone == ZONE_HIGHMEM;
 602#else
 603        return 0;
 604#endif
 605}
 606
 607static inline int is_highmem_idx(enum zone_type idx)
 608{
 609#ifdef CONFIG_HIGHMEM
 610        return (idx == ZONE_HIGHMEM ||
 611                (idx == ZONE_MOVABLE && zone_movable_is_highmem()));
 612#else
 613        return 0;
 614#endif
 615}
 616
 617static inline int is_normal_idx(enum zone_type idx)
 618{
 619        return (idx == ZONE_NORMAL);
 620}
 621
 622/**
 623 * is_highmem - helper function to quickly check if a struct zone is a 
 624 *              highmem zone or not.  This is an attempt to keep references
 625 *              to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
 626 * @zone - pointer to struct zone variable
 627 */
 628static inline int is_highmem(struct zone *zone)
 629{
 630#ifdef CONFIG_HIGHMEM
 631        int zone_off = (char *)zone - (char *)zone->zone_pgdat->node_zones;
 632        return zone_off == ZONE_HIGHMEM * sizeof(*zone) ||
 633               (zone_off == ZONE_MOVABLE * sizeof(*zone) &&
 634                zone_movable_is_highmem());
 635#else
 636        return 0;
 637#endif
 638}
 639
 640static inline int is_normal(struct zone *zone)
 641{
 642        return zone == zone->zone_pgdat->node_zones + ZONE_NORMAL;
 643}
 644
 645static inline int is_dma32(struct zone *zone)
 646{
 647#ifdef CONFIG_ZONE_DMA32
 648        return zone == zone->zone_pgdat->node_zones + ZONE_DMA32;
 649#else
 650        return 0;
 651#endif
 652}
 653
 654static inline int is_dma(struct zone *zone)
 655{
 656#ifdef CONFIG_ZONE_DMA
 657        return zone == zone->zone_pgdat->node_zones + ZONE_DMA;
 658#else
 659        return 0;
 660#endif
 661}
 662
 663/* These two functions are used to setup the per zone pages min values */
 664struct ctl_table;
 665struct file;
 666int min_free_kbytes_sysctl_handler(struct ctl_table *, int, struct file *, 
 667                                        void __user *, size_t *, loff_t *);
 668extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
 669int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, struct file *,
 670                                        void __user *, size_t *, loff_t *);
 671int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, struct file *,
 672                                        void __user *, size_t *, loff_t *);
 673int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,
 674                        struct file *, void __user *, size_t *, loff_t *);
 675int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int,
 676                        struct file *, void __user *, size_t *, loff_t *);
 677
 678extern int numa_zonelist_order_handler(struct ctl_table *, int,
 679                        struct file *, void __user *, size_t *, loff_t *);
 680extern char numa_zonelist_order[];
 681#define NUMA_ZONELIST_ORDER_LEN 16      /* string buffer size */
 682
 683#include <linux/topology.h>
 684/* Returns the number of the current Node. */
 685#ifndef numa_node_id
 686#define numa_node_id()          (cpu_to_node(raw_smp_processor_id()))
 687#endif
 688
 689#ifndef CONFIG_NEED_MULTIPLE_NODES
 690
 691extern struct pglist_data contig_page_data;
 692#define NODE_DATA(nid)          (&contig_page_data)
 693#define NODE_MEM_MAP(nid)       mem_map
 694
 695#else /* CONFIG_NEED_MULTIPLE_NODES */
 696
 697#include <asm/mmzone.h>
 698
 699#endif /* !CONFIG_NEED_MULTIPLE_NODES */
 700
 701extern struct pglist_data *first_online_pgdat(void);
 702extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
 703extern struct zone *next_zone(struct zone *zone);
 704
 705/**
 706 * for_each_online_pgdat - helper macro to iterate over all online nodes
 707 * @pgdat - pointer to a pg_data_t variable
 708 */
 709#define for_each_online_pgdat(pgdat)                    \
 710        for (pgdat = first_online_pgdat();              \
 711             pgdat;                                     \
 712             pgdat = next_online_pgdat(pgdat))
 713/**
 714 * for_each_zone - helper macro to iterate over all memory zones
 715 * @zone - pointer to struct zone variable
 716 *
 717 * The user only needs to declare the zone variable, for_each_zone
 718 * fills it in.
 719 */
 720#define for_each_zone(zone)                             \
 721        for (zone = (first_online_pgdat())->node_zones; \
 722             zone;                                      \
 723             zone = next_zone(zone))
 724
 725static inline struct zone *zonelist_zone(struct zoneref *zoneref)
 726{
 727        return zoneref->zone;
 728}
 729
 730static inline int zonelist_zone_idx(struct zoneref *zoneref)
 731{
 732        return zoneref->zone_idx;
 733}
 734
 735static inline int zonelist_node_idx(struct zoneref *zoneref)
 736{
 737#ifdef CONFIG_NUMA
 738        /* zone_to_nid not available in this context */
 739        return zoneref->zone->node;
 740#else
 741        return 0;
 742#endif /* CONFIG_NUMA */
 743}
 744
 745/**
 746 * next_zones_zonelist - Returns the next zone at or below highest_zoneidx within the allowed nodemask using a cursor within a zonelist as a starting point
 747 * @z - The cursor used as a starting point for the search
 748 * @highest_zoneidx - The zone index of the highest zone to return
 749 * @nodes - An optional nodemask to filter the zonelist with
 750 * @zone - The first suitable zone found is returned via this parameter
 751 *
 752 * This function returns the next zone at or below a given zone index that is
 753 * within the allowed nodemask using a cursor as the starting point for the
 754 * search. The zoneref returned is a cursor that represents the current zone
 755 * being examined. It should be advanced by one before calling
 756 * next_zones_zonelist again.
 757 */
 758struct zoneref *next_zones_zonelist(struct zoneref *z,
 759                                        enum zone_type highest_zoneidx,
 760                                        nodemask_t *nodes,
 761                                        struct zone **zone);
 762
 763/**
 764 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
 765 * @zonelist - The zonelist to search for a suitable zone
 766 * @highest_zoneidx - The zone index of the highest zone to return
 767 * @nodes - An optional nodemask to filter the zonelist with
 768 * @zone - The first suitable zone found is returned via this parameter
 769 *
 770 * This function returns the first zone at or below a given zone index that is
 771 * within the allowed nodemask. The zoneref returned is a cursor that can be
 772 * used to iterate the zonelist with next_zones_zonelist by advancing it by
 773 * one before calling.
 774 */
 775static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
 776                                        enum zone_type highest_zoneidx,
 777                                        nodemask_t *nodes,
 778                                        struct zone **zone)
 779{
 780        return next_zones_zonelist(zonelist->_zonerefs, highest_zoneidx, nodes,
 781                                                                zone);
 782}
 783
 784/**
 785 * for_each_zone_zonelist_nodemask - helper macro to iterate over valid zones in a zonelist at or below a given zone index and within a nodemask
 786 * @zone - The current zone in the iterator
 787 * @z - The current pointer within zonelist->zones being iterated
 788 * @zlist - The zonelist being iterated
 789 * @highidx - The zone index of the highest zone to return
 790 * @nodemask - Nodemask allowed by the allocator
 791 *
 792 * This iterator iterates though all zones at or below a given zone index and
 793 * within a given nodemask
 794 */
 795#define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
 796        for (z = first_zones_zonelist(zlist, highidx, nodemask, &zone); \
 797                zone;                                                   \
 798                z = next_zones_zonelist(++z, highidx, nodemask, &zone)) \
 799
 800/**
 801 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
 802 * @zone - The current zone in the iterator
 803 * @z - The current pointer within zonelist->zones being iterated
 804 * @zlist - The zonelist being iterated
 805 * @highidx - The zone index of the highest zone to return
 806 *
 807 * This iterator iterates though all zones at or below a given zone index.
 808 */
 809#define for_each_zone_zonelist(zone, z, zlist, highidx) \
 810        for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
 811
 812#ifdef CONFIG_SPARSEMEM
 813#include <asm/sparsemem.h>
 814#endif
 815
 816#if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
 817        !defined(CONFIG_ARCH_POPULATES_NODE_MAP)
 818static inline unsigned long early_pfn_to_nid(unsigned long pfn)
 819{
 820        return 0;
 821}
 822#endif
 823
 824#ifdef CONFIG_FLATMEM
 825#define pfn_to_nid(pfn)         (0)
 826#endif
 827
 828#define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT)
 829#define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT)
 830
 831#ifdef CONFIG_SPARSEMEM
 832
 833/*
 834 * SECTION_SHIFT                #bits space required to store a section #
 835 *
 836 * PA_SECTION_SHIFT             physical address to/from section number
 837 * PFN_SECTION_SHIFT            pfn to/from section number
 838 */
 839#define SECTIONS_SHIFT          (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)
 840
 841#define PA_SECTION_SHIFT        (SECTION_SIZE_BITS)
 842#define PFN_SECTION_SHIFT       (SECTION_SIZE_BITS - PAGE_SHIFT)
 843
 844#define NR_MEM_SECTIONS         (1UL << SECTIONS_SHIFT)
 845
 846#define PAGES_PER_SECTION       (1UL << PFN_SECTION_SHIFT)
 847#define PAGE_SECTION_MASK       (~(PAGES_PER_SECTION-1))
 848
 849#define SECTION_BLOCKFLAGS_BITS \
 850        ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
 851
 852#if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
 853#error Allocator MAX_ORDER exceeds SECTION_SIZE
 854#endif
 855
 856struct page;
 857struct mem_section {
 858        /*
 859         * This is, logically, a pointer to an array of struct
 860         * pages.  However, it is stored with some other magic.
 861         * (see sparse.c::sparse_init_one_section())
 862         *
 863         * Additionally during early boot we encode node id of
 864         * the location of the section here to guide allocation.
 865         * (see sparse.c::memory_present())
 866         *
 867         * Making it a UL at least makes someone do a cast
 868         * before using it wrong.
 869         */
 870        unsigned long section_mem_map;
 871
 872        /* See declaration of similar field in struct zone */
 873        unsigned long *pageblock_flags;
 874};
 875
 876#ifdef CONFIG_SPARSEMEM_EXTREME
 877#define SECTIONS_PER_ROOT       (PAGE_SIZE / sizeof (struct mem_section))
 878#else
 879#define SECTIONS_PER_ROOT       1
 880#endif
 881
 882#define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
 883#define NR_SECTION_ROOTS        (NR_MEM_SECTIONS / SECTIONS_PER_ROOT)
 884#define SECTION_ROOT_MASK       (SECTIONS_PER_ROOT - 1)
 885
 886#ifdef CONFIG_SPARSEMEM_EXTREME
 887extern struct mem_section *mem_section[NR_SECTION_ROOTS];
 888#else
 889extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
 890#endif
 891
 892static inline struct mem_section *__nr_to_section(unsigned long nr)
 893{
 894        if (!mem_section[SECTION_NR_TO_ROOT(nr)])
 895                return NULL;
 896        return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
 897}
 898extern int __section_nr(struct mem_section* ms);
 899extern unsigned long usemap_size(void);
 900
 901/*
 902 * We use the lower bits of the mem_map pointer to store
 903 * a little bit of information.  There should be at least
 904 * 3 bits here due to 32-bit alignment.
 905 */
 906#define SECTION_MARKED_PRESENT  (1UL<<0)
 907#define SECTION_HAS_MEM_MAP     (1UL<<1)
 908#define SECTION_MAP_LAST_BIT    (1UL<<2)
 909#define SECTION_MAP_MASK        (~(SECTION_MAP_LAST_BIT-1))
 910#define SECTION_NID_SHIFT       2
 911
 912static inline struct page *__section_mem_map_addr(struct mem_section *section)
 913{
 914        unsigned long map = section->section_mem_map;
 915        map &= SECTION_MAP_MASK;
 916        return (struct page *)map;
 917}
 918
 919static inline int present_section(struct mem_section *section)
 920{
 921        return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
 922}
 923
 924static inline int present_section_nr(unsigned long nr)
 925{
 926        return present_section(__nr_to_section(nr));
 927}
 928
 929static inline int valid_section(struct mem_section *section)
 930{
 931        return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
 932}
 933
 934static inline int valid_section_nr(unsigned long nr)
 935{
 936        return valid_section(__nr_to_section(nr));
 937}
 938
 939static inline struct mem_section *__pfn_to_section(unsigned long pfn)
 940{
 941        return __nr_to_section(pfn_to_section_nr(pfn));
 942}
 943
 944static inline int pfn_valid(unsigned long pfn)
 945{
 946        if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
 947                return 0;
 948        return valid_section(__nr_to_section(pfn_to_section_nr(pfn)));
 949}
 950
 951static inline int pfn_present(unsigned long pfn)
 952{
 953        if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
 954                return 0;
 955        return present_section(__nr_to_section(pfn_to_section_nr(pfn)));
 956}
 957
 958/*
 959 * These are _only_ used during initialisation, therefore they
 960 * can use __initdata ...  They could have names to indicate
 961 * this restriction.
 962 */
 963#ifdef CONFIG_NUMA
 964#define pfn_to_nid(pfn)                                                 \
 965({                                                                      \
 966        unsigned long __pfn_to_nid_pfn = (pfn);                         \
 967        page_to_nid(pfn_to_page(__pfn_to_nid_pfn));                     \
 968})
 969#else
 970#define pfn_to_nid(pfn)         (0)
 971#endif
 972
 973#define early_pfn_valid(pfn)    pfn_valid(pfn)
 974void sparse_init(void);
 975#else
 976#define sparse_init()   do {} while (0)
 977#define sparse_index_init(_sec, _nid)  do {} while (0)
 978#endif /* CONFIG_SPARSEMEM */
 979
 980#ifdef CONFIG_NODES_SPAN_OTHER_NODES
 981bool early_pfn_in_nid(unsigned long pfn, int nid);
 982#else
 983#define early_pfn_in_nid(pfn, nid)      (1)
 984#endif
 985
 986#ifndef early_pfn_valid
 987#define early_pfn_valid(pfn)    (1)
 988#endif
 989
 990void memory_present(int nid, unsigned long start, unsigned long end);
 991unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
 992
 993/*
 994 * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
 995 * need to check pfn validility within that MAX_ORDER_NR_PAGES block.
 996 * pfn_valid_within() should be used in this case; we optimise this away
 997 * when we have no holes within a MAX_ORDER_NR_PAGES block.
 998 */
 999#ifdef CONFIG_HOLES_IN_ZONE
1000#define pfn_valid_within(pfn) pfn_valid(pfn)
1001#else
1002#define pfn_valid_within(pfn) (1)
1003#endif
1004
1005#endif /* !__GENERATING_BOUNDS.H */
1006#endif /* !__ASSEMBLY__ */
1007#endif /* _LINUX_MMZONE_H */
1008
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